1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
#ifndef BOOST_STATECHART_DETAIL_COUNTED_BASE_HPP_INCLUDED
#define BOOST_STATECHART_DETAIL_COUNTED_BASE_HPP_INCLUDED
//////////////////////////////////////////////////////////////////////////////
// Copyright 2002-2006 Andreas Huber Doenni
// Distributed under the Boost Software License, Version 1.0. (See accompany-
// ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//////////////////////////////////////////////////////////////////////////////
#include <boost/smart_ptr/detail/atomic_count.hpp>
#include <boost/config.hpp> // BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
namespace boost
{
namespace statechart
{
namespace detail
{
template< bool NeedsLocking >
struct count_base
{
count_base() : count_( 0 ) {}
mutable boost::detail::atomic_count count_;
};
template<>
struct count_base< false >
{
count_base() : count_( 0 ) {}
mutable long count_;
};
//////////////////////////////////////////////////////////////////////////////
template< bool NeedsLocking = true >
class counted_base : private count_base< NeedsLocking >
{
typedef count_base< NeedsLocking > base_type;
public:
//////////////////////////////////////////////////////////////////////////
bool ref_counted() const
{
return base_type::count_ != 0;
}
long ref_count() const
{
return base_type::count_;
}
protected:
//////////////////////////////////////////////////////////////////////////
counted_base() {}
~counted_base() {}
// do nothing copy implementation is intentional (the number of
// referencing pointers of the source and the destination is not changed
// through the copy operation)
counted_base( const counted_base & ) : base_type() {}
counted_base & operator=( const counted_base & ) { return *this; }
public:
//////////////////////////////////////////////////////////////////////////
// The following declarations should be private.
// They are only public because many compilers lack template friends.
//////////////////////////////////////////////////////////////////////////
void add_ref() const
{
++base_type::count_;
}
bool release() const
{
BOOST_ASSERT( base_type::count_ > 0 );
return --base_type::count_ == 0;
}
};
} // namespace detail
} // namespace statechart
} // namespace boost
#endif
|
